1. Field of the Invention
The present invention relates generally to the technical field of optical scanning and, more particularly, to fingerprint scanners used for personal verification and/or identification.
2. Description of the Prior Art
Biometric identification techniques, e.g. fingerprints and mug shots, have been employed for many years in the criminal justice system for identifying individuals. For example, financial institutions in several states have begun or are launching programs that require fingerprinting non-customers wishing to cash a check at a teller window. The financial institutions estimate that such fingerprinting will reduce check fraud 40% to 60%. To reduce losses from fraud, commercial enterprises are presently investigating various biometric identification systems to reduce fraud. Different biometric identification systems that are now in use or being tested by financial institutions use various biometric characteristics such as signature dynamics, hand geometry, fingerprints, retina scans, iris scans, or voice recognition, to identify or verify an individual's identity.
While traditional financial transaction systems experience losses from fraud such as those outlined above, emerging electronic commercial systems, such as the global computer information network known as the Internet, are far less secure than the traditional systems. Obviously the potential for fraud in these emerging electronic commercial systems exceeds that of traditional systems. Truly secure communication via the Internet, especially for financial transactions or for gaining access to an intra-company network, frequently require that the sender or requester be identified beyond a reasonable doubt. Since computer user-IDs and passwords are easily compromised, truly secure electronic communication necessarily requires information in addition to merely the user-ID and password.
To address the user verification problem both for traditional and electronic commerce, a number of fingerprint identification systems have recently been introduced that, using a personal computer, identify an individual. For example, a major keyboard manufacturer has recently announced a keyboard that includes a fingerprint imaging system. This particular product uses a CCD imaging device and conventional optics to capture the fingerprint image. Unfortunately, present systems for capturing fingerprint data, and as well as other competing biometric identification systems, are all too expensive to permit widespread dissemination, such as at every point of sale terminal and/or automatic teller machine terminal. Consequently, unless the cost of biometric identification systems decrease greatly, their widespread use in the immediate future to reduce financial transaction fraud appears unlikely.
Another application for biometric identification that requires widespread dissemination of biometric sensors exists for expensive portable devices such as laptop and notebook computers. In recent years, thefts of laptop and notebook computers have increased markedly due to small size of laptop and notebook computers and their comparatively high market value, e.g. $2,000.00 to $7,000.00. However, such a market value for a laptop or notebook computer is, in many instances, only a small fraction of the true economic damage caused by its theft due to a concurrent loss of valuable information that its owner has stored in the computer. If a portable device such as a laptop or notebook computer were trainable to biometrically recognize its owner and to operate only after biometrically confirming the user's identity, a stolen laptop or notebook computer would be worthless. However, a biometric sensor suitable for use in a laptop or notebook computer, or other portable device such as a cellular telephone, must occupy a minuscule amount of space. Consequently, widespread adoption of biometric identification to deter theft or illicit use of portable electronic devices such as laptop and notebook computers and cellular telephones requires not only an inexpensive biometric sensor, it also requires an extremely compact biometric sensor.
Present fingerprint scanners generally employ an optical platen to which a subject touches a finger while the scanner acquires the fingerprint data. If the optical platen gets scratched or contaminated, then it might require replacement. Furthermore, structural materials used in fabricating the optical platen, such as glass or polymeric materials, are generally not compliant, and therefore acquiring accurate fingerprint data requires that the subject press the finger forcefully against the optical platen.